K. Schild. "Undecidability of U ." KIT Report 67, TU Berlin, D-1000 Berlin, West Germany, 1988.  Home/Search   Document Not in Database   Summary   Related Articles

.... a concept denoting the entire domain of an interpretation [BL84] Several complexity results showed that already for seemingly slight extensions of FL Gamma the subsumption problem is co NP hard [LB87, Neb88] Other work identified languages with undecidable subsumption problem [Pat89, Sch89, Sch88] The first nontrivial subsumption algorithm was given by Schmidt Schau and Smolka [SS88] for the language ALC, which extends FL Gamma by allowing for arbitrary logical connectives and role quantification as constructs. The algorithm is even optimal, since it requires linear space and they ....

....which can be decided with linear space. 6 Conclusion This paper is a contribution to exploring the frontier between concept languages with decidable and such with undecidable subsumption problem. Former efforts concentrated on finding minimal languages with undecidable subsumption problem [Pat89, Sch88, Sch89] We complement this work by givingv satisfiability and subsumption checking algorithms for languages that are, to the best of our knowledge, the richest for which these problems are known to be decidable. Nevertheless, we feel that they can still be extended by further constructs, like ....

K. Schild. "Undecidability of U ." KIT Report 67, TU Berlin, D-1000 Berlin, West Germany, 1988.

Online articles have much greater impact   More about CiteSeer.IST   Add search form to your site   Submit documents   Feedback  

CiteSeer.IST - Copyright Penn State and NEC